package Leetcode第二期;


/**
 * @author : K k
 * @date : 11:10 2020/9/19
 */
public class 合并两个有序链表_21 {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        ListNode head=new ListNode(0);
        ListNode cur=head;

        while (l1!=null || l2!=null){
            //终结条件是两个链表都为null
            if (l1!=null && l2!=null){
                if (l1.val<l2.val){
                    cur.next=l1;
                    l1=l1.next;
                }else {
                    cur.next=l2;
                    l2=l2.next;
                }
            }
            if (l1==null && l2!=null){
                cur.next=l2;
                l2=l2.next;
            }
            if (l2==null && l1!=null){
                cur.next=l1;
                l1=l1.next;
            }
            cur=cur.next;
        }
        return head.next;
    }
}
